Donald Trump. Getty Images/Pool Citi thinks people should start to think about the I-word when it comes to Donald Trump's presidency: impeachment.

Tina Fordham, the chief global political analyst at Citi, said the possibility of impeachment was still low. But after the release of emails between Donald Trump Jr. and a music publicist believed to have helped arrange a June 2016 meeting with a Russian attorney in which Trump Jr. was hoping to get damaging information about Hillary Clinton, the prospects of a Trump ouster are on the rise, she said.

"Do these most recent developments, which suggest that key Trump advisers, including his son Donald Trump Jr. and son-in-law Jared Kushner met with a Russian lawyer (who had previously lobbied in Washington against the 2012 Magnitsky sanctions act), change the potential for impeachment?" Fordham wrote in a note. "It is of course too soon to say, but we believe the risk of impeachment proceedings is now higher than before, even if still not our base case."

The biggest thing that would be in the way of impeachment is congressional Republicans — even though GOP lawmakers have said they are "troubled" by the Trump-Russia headlines, they're unlikely to impeach Trump while they have a majority in both chambers, Fordham said.

"With this in mind, despite remarks from senior congressional Republicans suggesting unease with the Trump administration, it would be highly unusual and indeed likely politically costly to the party's electoral prospects to pursue impeachment proceedings against a president of their own party, particularly with midterm elections a little over a year away," Fordham said.

Despite this, Tuesday's news could mean Republicans' legislative agenda will stay stuck in place— that items like tax reform, economic stimulus, and the repeal and replacement of the Affordable Care Act could be further off than the GOP wants.

The continued Russia-related headlines, according to the Citi analyst, could also damage Republican brand in future elections.

"Impeachment proceedings may never be brought, but the risk of reputational damage to the Republican Party and those members of Congress up for re-election in November 28 midterms will be a further risk factor to consider," Fordham said.